A hydraulic vehicle brake with an electrically actuatable parking brake device is known, for example, from DE 101 50 803 B4, which is incorporated by reference. In the known vehicle brake there is provided a gear unit which converts the rotary motion of the electric motor into a longitudinal motion of the brake piston in order to produce a parking brake force, on the operating principle of a threaded nut/spindle arrangement. According to an exemplary embodiment, this gear unit is in the form of a so-called “spindle/recirculating ball sleeve arrangement”, also referred to as a ball screw or recirculating ball spindle. These ball screws comprise a threaded spindle and a threaded nut which contact one another via a plurality of rolling elements.
A threaded nut having a rolling element arrangement without so-called ball recirculation is known from the German utility model DE 76 40 810 U, which is incorporated by reference. In this case the rolling elements have limited mobility between two stops rigidly connected to the threaded nut. A disadvantage of this arrangement is that the stops are inserted into the threaded nut from outside, as pins through a bore. Because the bore must meet the thread convolution precisely when drilling into the threaded nut from outside, production is difficult.
There are also brakes with purely electromechanical actuation (EMB) which are provided for brake-by-wire brake systems and which require a ball screw constructed identically in principle.